Photocatalytic upgrading of 5-hydroxymethylfurfural – aerobic or anaerobic?

Aerobic photocatalysis generates ROS to oxidise HMF into DFF and FDCA with co-production of H 2 O 2 that potentially induce over-oxidation. Anaerobic photocatalysis enables ambient HMF oxidation with simultaneous HER, or hydrogenation of HMF to BHMF.